Share This

The octocopter follows a pre-defined route by means of a ground marking system. The autonomous measuring probe which is mounted on the octocopter is equipped with three antennas arranged at right angles to one another, and with its own GPS receiver. The integrated microprocessor processes the data flow of the three-channel HF receiver as well as the GPS position, records these data in real time and provides them with a timestamp. The measured data can be evaluated at any subsequent moment.

Related Articles

Researchers from the Physikalisch-Technische Bundesanstalt (PTB), together with FCS Flight Calibration Services GmbH from Braunschweig, have developed a measuring system which, hanging from a helicopter, detects the electric field strength as well as the signal contents of air-traffic control navigation systems with unprecedented accuracy. They had hardly developed this system when a future potential application field of an extended hovering facility was found: the evaluation of recorded measurement data could be used already in the planning phase of wind farms to find out to what extent the planned wind farms would influence the operation of neighbouring radar facilities used for air-traffic control, aerial defence or meteorological observations. A miniaturized -- and still strongly simplified -- version of the measuring arrangement has already made its first test flights on an octocopter.

Sometimes, societal and political developments evolve as competing projects: on the one hand, the "Energiewende" (energy transition) leads to numerous wind farms being erected, on the other hand, the radar surveillance systems used by meteorologists, air-traffic control and aerial defence ensure safety. The problem is that radar waves are scattered when they hit the rotor blades of windmills in a large wind farm; they can interfere with the wanted signals to such an extent that the sensor provides erroneous information. Quite a few wind energy projects have currently been put on hold because the operators of neighbouring radar facilities are often no longer willing to accept external experts' opinions based on pure simulation models as the proof of the undisturbed coexistence of the two technologies. This is due to the fact that the simulation of the wave propagation requires numerous assumptions which could to date not be verified by measurements, so that interactions with wind farms can no longer be assessed with sufficient safety and certitude. This is where the new system developed by PTB and FCS Flight Calibration Services GmbH comes in: it is able to provide the underlying data for simulation models and thus help experts derive more reliable predictions from improved models for the authorities issuing the authorizations.

About the technology

The core piece of this technology is a jointly developed antenna and receiver system. In its previous design, it hangs down from a helicopter and can measure the electromagnetic field strength at any random location in space and save the measured data as well as the exact location (GPS supported by EGNOS) with a very high sampling rate in real time. Successful tests have already demonstrated that this system is capable of measuring the electromagnetic far field which is necessary for a flawless signal transmission (e.g. between an instrument landing system and an aircraft) as precisely as required by the International Civil Aviation Organization (ICAO). The measurement is traceable to the International System of Units (SI) -- i.e. the highest possible standard -- which ensures its comparability. No one in Europe had ever achieved this before.

Thorsten Schrader (Head of PTB's "High Frequency and Electromagnetic Fields" Department) and his research colleagues and partners have now miniaturized this antenna system to fit it onto an octocopter (i.e. a miniaturized helicopter approx. 80 cm wide and equipped with 8 rotors). On such aerial vehicles, it might soon be possible to use the sensor at places where wind farms already exist or where they are planned in order to acquire data with regard to the field strength and to modified signal contents at any selected coordinates over any random periods. The researchers intend to use it in a first step to metrologically detect the real-time dynamic change in the electromagnetic wave propagation caused by wind farms, to analyze it and feed it into a (preferably) simple model of the electromagnetic data transmission channel.

The innovative approach provided by this project (WERAN -- German acronym for "Interaction between wind farms and radar/navigation") consists in dividing the complex estimation of the disturbances caused to radars by wind farms into metrologically detectable intermediate steps and in comparing only compatible quantities from numerical simulations and measurements with each other. The project is funded by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU). PTB's research partners are the enterprises FCS and "steep" as well as the Leibniz Universitδt Hannover.

More From ScienceDaily

More Matter & Energy News

Featured Research

Mar. 31, 2015  Researchers have recorded the first direct observations of the micro-scale mechanisms behind the ability of skin to resist tearing. The results could be applied to the improvement of artificial skin, ... full story

Mar. 31, 2015  A year ago, researchers showed that their software endowed the walking robot Hector with a simple form of consciousness. Their new research goes one step further: they have now developed a software ... full story

Mar. 31, 2015  Landfills can make a profit from all their rotting waste and a new patent explains exactly how to make the most out of the stinky garbage sites. Decomposing trash produces methane, a landfill gas ... full story

Mar. 31, 2015  Scientists have achieved an unprecedented level of control over defects in liquid crystals that can be engineered for applications in liquid matter photonics. Sitting with a joystick in the comfort ... full story

Mar. 30, 2015  Neuroscientists are taking inspiration from natural motor control to design new prosthetic devices that can better replace limb function. Researchers have tested a range of brain-controlled devices ... full story

Mar. 30, 2015  Speaking in public is the top fear for many people. Now, researchers have developed an intelligent user interface for 'smart glasses' that gives real-time feedback to the speaker on volume modulation ... full story

Mar. 30, 2015  By studying the morphology and physiology of plants with tiny conical "hairs" or microfibers on the surface of their leaves, such as tomatoes, balsam pears and the flowers Berkheya purpea and Lychnis ... full story

Mar. 30, 2015  In the first study of its kind, scientists quantitatively show that electric vehicles will meet the daily travel needs of drivers longer than commonly assumed. They found that batteries that have ... full story

Mar. 30, 2015  One researcher has developed a clever solution to gather naturalistic driving data. For several years, she has been using a detailed driving simulator to study how participants respond to ... full story

Bionic Ants Could Be Tomorrow's Factory Workers

Reuters - Innovations Video Online (Mar. 30, 2015)  Industrious 3D printed bionic ants working together could toil in the factories of the future, says German technology company Festo. The robotic insects cooperate and coordinate their actions and movements to achieve a common aim. Amy Pollock reports.
Video provided by Reuters

Related Stories

Feb. 10, 2014  They can be seen from afar -- the blinking beacons on wind turbines -- intended to warn approaching aircraft at night. However, the continual blinking disturbs many people. Beacons that only switch ... full story

Jan. 2, 2014  Researchers have found that an increase in the use of wind power generation can make the power grid more fragile and susceptible to disruptions. But the researchers didn't just identify the ... full story

Aug. 6, 2013  A new report details how more Americans are installing wind turbines near their homes, businesses and farms to generate their own energy as part of a growing field of wind power called distributed ... full story

Dec. 20, 2010  Scientists are researching how radar weather instruments can help improve predictions on when and how strongly winds will blow. They're testing the instruments from a working wind farm in ... full story

Oct. 22, 2010  Physicists and engineers have installed a radar system on the Falkland Islands to monitor the upper atmosphere activity which creates the 'Southern Lights'. The new radar joins a network of ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.